how to connect from PC to PLC2 via PLC1

[Lubomir Pavlansky 0]

Hi all, In company where I work we use Omron plc on all equipments. All these plc are connected each other and master plc via Controler Link Unit CLK-23. This is our production equipments network. Some PLC has also ethernet card. Via this card I´m able to connect to PLC. Now,a little expample to explain my problem: I´m connected to PLC1 via ethernet. PLC1 is connected to PLC2 via CLK-23. And question is : how can I connect to PLC2? But via PLC1. All this I asked because of I want to use CX Server DDE manager to collect data from line to excel table. With direct connection no problem. But I need to do real time connection with all plc on the line. Thank you for your help. BR, Lubomir

[Homer_BL 2]

Hi, Lubomir! Open a new project. Put both PLC's in the same project (PLC1 and PLC2) Doubleclick on PLC2 In Network type, choose (PLC1) - to make it a Gateway for connection to PLC2. In settings, choose Node address and Unit No od CLK board you have in PLC2. Thats all. Once i worked wtih 11 CQM1H/CJ1 (with CLK units) and I was able to open ALL 11 PLCs (simulaneously ONLINE) when connectes to first PLC via serial cable only. Thats great.

[Lubomir Pavlansky 0]

Hi Sparky, I did it by this way also before, but it doesn´t work. But I tried your way also with Toolbus connection and it was working. No problem to connect to whole line. But with ethernet connection it doesnt work. I received also reply from myomron.com, that problem should be with routing table. I need to do some routing table and there define all routes. Maybe later I will try also this way. Thank you for your help. It was good advice for me. BR,Lubo

[Michael Walsh 268]

I agree with myomron.com, your issue is that you need routing tables. Suppose that this is your network (the network, node and unit numbers are arbitrary): You need to set up routing tables in each PLC. The main issue is that the PLC with only the CLK module on it does not know how to get a response back to the Ethernet unit. That is called a remote network. When you connect through Toolbus, then there are not two networks involved and it can get a response back. So, using the CX-Net configuration tool or CX-Integrator, you can create and install routing tables in both PLCs. I have attached pictures of the routing tables that would be used for the setup above. For the PLC with both Ethernet and CLK modules: This specifies that Unit #0 (SIOU = Unit #) is the connection to network 2 and that unit number 1 (SIOU = Unit #) is the connection to network 1. Both of these networks are local (meaning that there is a direct connection to this PLC), so both entries are in the local network side. For the PLC with only a CLK Module: For this routing table, the only local network is the CLK network. So, we map unit #0 to network 2. The ethernet network is not a local network (there is no ethernet connection on this computer). So, this connection must be made in the remote network table. The remote network table says, "to get to remote network 1, go out on network 2 and go to Node 1". You must connect with toolbus to each PLC and transfer these routing tables into the PLC. Then, use the settings below in CX-Programmer to connect using Ethernet through the left PLC to the PLC on the right. Of course, you must set the appropriate IP address and node number in the driver tab as well. Good luck! Edited 3 Dec 2010 by Michael Walsh

[Jay Anthony 118]

Good work, Mike!

[Lubomir Pavlansky 0]

Hi Michael, thank you for your help. And sorry for my delay. Finally, I did it without creating routing table. I connected to PLC1 directly with toolbus and to PLC2 via PLC1. So It was not necessary to do a routing table. But now I have another problem. And I think I will have to do routing table. You can see at the attached image. I want to connect from PLC1 to PLC2 through MPLC. PLC1 and PLC2 are in different networks. Dear Michael or other kindly people, could you help me with creating routing table? Another questio is, I will have to transfer routing table also to MPLC? I´m affraid I´ll do something wrong with MPLC. My boss would kill me:). Thank you very much. And happy new year :) Lubomir